1. Field of the Invention.
The present invention generally relates to fluid bearings for supporting a rotary device, and, more particularly, to providing fluid support for a flywheel in a press machine and to developing fluid lubrication for an anti-rotationalkey.
2. Description of the Related Art.
Mechanical presses such as straight side presses and gap frame presses for stamping and drawing are provided with a frame structure having a crown and bed and a slide member supported within the frame for reciprocating motion relative to the bed. A crankshaft is provided to translate rotational motion generated by the press machine into reciprocal mechanical activity that is transmitted to the slide through a connecting arm. An upper die is mounted to the slide. The lower die is mounted to a bolster, which in turn is connected to the bed. Mechanical presses of this construction are widely used for blanking and drawing operations and vary substantially in size and available tonnage depending upon their intended use.
The primary source for stored mechanical energy and rotational actuation is the flywheel assembly, which in standard construction is located between the main drive motor and clutch. The flywheel and its associated bearing are mounted on either the driveshaft, crankshaft, or the press frame by use of a quill. The main drive motor replenishes the flywheel with rotational energy as the same becomes depleted from the flywheel during press stamping operations when the clutch couples the flywheel to the press driven parts and causes energy to be drawn away and transferred to other areas of the machine. In particular, during engagement of the clutch, the flywheel drops in speed as the press driven parts are thereby powered to reach press running speed. The flywheel rotates in unison with the clutch during operative engagement, whereas the flywheel bearings have no relative rotation except in configurations where a quill is used, in which case relative rotation is present.
The installation of flywheel assemblies into conventional machines such as mechanical presses makes use of anti-friction roller or ball bearings to mount the flywheel to its support. Bearings of this type feature low lubrication requirements, low viscous drag, and a statistically predictable lifetime. However, the bearings are susceptible to vibration and shock, which may cause brinelling, false brinelling, fretting corrosion, and consequential damage to the bearing races, hub bores and shaft.
Anti-rotational keys provide one form of mechanical coupling used in constructing and assembling the components of a press machine. This type of coupling between adjacent mechanical parts, for example, might employ a key element projecting from one part that is mated into a corresponding channel of another part defining a key receiving area. The registration of respective key elements inhibits relative rotation between the associated mechanical parts. However, due to the clearance that exists between the mated key elements, there will be unavoidable metal-to-metal contact. occurring during press operation that will continuously wear away material from both elements, which may eventually lead to unacceptable part displacements.